Can any of you Expert Yahoo SEO's out there give me an example of a well-formed, well written description meta tag for Yahoo that ranks well if the keyword phrase is, let's say, 'Boston Celtics Tickets'?

Would this be good or not so good and how could it be improved?

The keyword phrase is 'Boston Celtics Tickets' - here's my shot at the description tag:

"Boston Celtics tickets offering Boston tickets - with 2005 regular and playoff NBA Tickets, Celts tix, hoops tickets, theatre tickets, including Boston Celtics basketball tickets, and cheap and sold out tickets online."

Thanks,
Jay

Your description doesn't make too much sense. Something like this would be much better:

"Offering Boston Celtics tickets for the 2004-2005 regular season as well as NBA playoff tickets. Additionally purchase theatre tickets and sold out tickets online."

What ever the description is going to be it should be read in conjunction with the page title and carry the same theme forward.

I think you should resrict yourself to selling Boston Celtics and NBA playoff tickets on one page and theater and sold out tickets on other pages and in that case if your page title is something like

Boston Celtics tickets and NBA playoff tickets

Then you can carry on with something that uses your best keywords and explains why the viewer should visit your page to buy depending on what is your USP, good prices plenty of tickets, etc